cnss2: Add NULL check for 'dev' pointer

Add NULL check for 'dev' pointer before passing to
cnss_bus_dev_to_plat_priv function.

Change-Id: I8ab93a71219638e4b66d3b9fdcb164e052385129
CRs-Fixed: 3364740

cnss2/main.c

@@ -449,9 +449,15 @@ EXPORT_SYMBOL(cnss_wlan_enable);
 
 int cnss_wlan_disable(struct device *dev, enum cnss_driver_mode mode)
 {
-	struct cnss_plat_data *plat_priv = cnss_bus_dev_to_plat_priv(dev);
 	int ret = 0;
+	struct cnss_plat_data *plat_priv;
+
+	if (!dev) {
+		cnss_pr_err("Invalid dev pointer\n");
+		return -EINVAL;
+	}
 
+	plat_priv = cnss_bus_dev_to_plat_priv(dev);
 	if (!plat_priv)
 		return -ENODEV;
 
@@ -574,8 +580,14 @@ EXPORT_SYMBOL(cnss_athdiag_write);
 
 int cnss_set_fw_log_mode(struct device *dev, u8 fw_log_mode)
 {
-	struct cnss_plat_data *plat_priv = cnss_bus_dev_to_plat_priv(dev);
+	struct cnss_plat_data *plat_priv;
+
+	if (!dev) {
+		cnss_pr_err("Invalid dev pointer\n");
+		return -EINVAL;
+	}
 
+	plat_priv = cnss_bus_dev_to_plat_priv(dev);
 	if (!plat_priv)
 		return -ENODEV;